The present invention relates to improvements in paper making machines, and more particularly to a twin wire machine of the type capable of making a multi-ply paper web with improved means for controlling the relative running positions of the wires.
In high speed traveling wire paper making machines, the positions of the wire must be controlled so that they do not skew sideways and so that the web remains in a uniform lateral position during continuing operation. Conventionally, this has been done by mounting the supporting bearing at one end of one of the wire support rolls so that the bearing can shift forward or rearward in a machine direction to regulate the running position of the wire. That is, as the end of the roll shifts either toward the oncoming wire or with the direction of the traveling wire, the wire will tend to skew to the left or right depending on how the roll end changes.
With twin wire machines wherein two wires are run together in close running relationship along a forming run, the position of both wires must be controlled. An example of such an installation is in a multi-ply paper web machine wherein the lower wire is a fourdrinier, and a series of upper forming wires are pressed into the fourdrinier at successive locations with an additional layer of web formed at each location. It has been found to involve a relatively complicated and expensive equipment to control the lateral position of the upper looped forming wire by constructing one of the guide rolls so as to be shiftable. Such shiftable roll requires equipment strong enough to support the bearings at each end with the bearing at one end being pivotally mounted and the bearing at the other end being shiftably mounted so as to shift forward or rearwardly in the direction of wire travel.
An important object of the present invention is to provide an improved device which will make it unnecessary to provide a shiftable wire guide roll within the looped forming wire of a twin wire machine.
A further object of the invention is to provide an improved twin wire machine wherein the tracking location of the mating or auxiliary wire of a twin wire machine is controlled by supporting the wire on rotatable rolls fixedly located on a frame and shifting the position of the entire frame relative to the main fourdrinier wire.
A still further object of the invention is to provide an improved method and structure for changing the tracking location of the supporting frame and rolls of a mating wire in a twin wire paper making machine.
Other objects, advantages and features will become more apparent, as well as equivalent structures which are intended to be covered herein, with the teaching of the principles of the present invention in connection with the disclosure of the preferred embodiments thereof in the specification, claims and drawings, in which: